The petroleum industry is allocating more and more resources to imaging subsoil rock structures in an effort to identify potential oil reserves underground. For example, large numbers of datasets of three-dimensional (3-D) seismic data volume are being generated through various exploration activities. The datasets are typically representations of changes in acoustic impedance of underground earth as a function of, for example, depth underneath the ground. Most seismic reflections in a 3-D seismic dataset are manifestations of rock layering or horizons. These manifestations represent the sub-horizontal sedimentary layering within petroleum-bearing sedimentary basins. A geologically trained professional may recognize the patterns presented by these 3-D datasets and therefore may be able to extract useful insight information into the rock formation and geological structure, as well as such things as the location and shape of geological structures in which hydrocarbons may be trapped.
Because of the complexity and size of the 3-D seismic data or datasets, various image-processing techniques have been developed, for example, to process the 3-D seismic data in order to provide a reasonable interpretation of the seismic data. Among the various techniques, one of the most notable is the horizon auto-picker. A horizon may be for example a change in lithology in the crust of earth or a chronostratigraphic boundary represented in a 3-D seismic volume by a characteristic trace shape over a certain time or depth interval. Horizons may be surfaces representing individual sedimentary layers of rock. A horizon map generated by a horizon auto-picker may provide petroleum exploration professionals, for example, with certain level of understanding of the geology and geometry of the subsurface of the earth. To date, a number of horizon auto-picker tools have been successfully developed and some are commercially available.
With the relative success in the horizon auto-picker tools, researchers have now moved to the relatively more difficult tasks of performing seismic fault geometry extraction or identification. Faults may include fracture surfaces in the subsurface rock caused by tectonic forces or other forces, or other displacements between underground formations or regions. Underground forces often lead to a near-vertical relative displacement between adjacent rock formations on both sides of the fracture. In seismic images, faults may be recognized by an abrupt vertical displacement of seismic sequences along some plane, which may be known as fault plane.